The Infineon BCR 153F E6327 is a PNP pre-biased transistor in a SOT-723 surface-mount package. The base and emitter-base bias resistors are both 2.2 kOhms, which sets the turn-on threshold and limits base drive without external components. This is the kind of part you see in low-current switching and interface circuits — relay drivers, level shifters, or as a simple inverter stage on a digital I/O line — where you want to save board space and BOM count by integrating the bias network into the transistor die.
This part carries an Obsolete lifecycle status. The laser etch and date-code consistency matter here: a clean trace back to Infineon's own marking font and package plant is the baseline for accepting any lot. Because this is an obsolete PNP pre-biased transistor, there is no official Infineon successor listed for the BCR 153F E6327. Any replacement evaluation should start with the resistor values — 2.2 kOhms on both base and emitter-base — and the SOT-723 footprint. A same-function PNP pre-biased part from another manufacturer with matching R1/R2 and the same pinout is the practical cross-shop target.
Key ratings and the decisions they drive
The 50 V collector-emitter breakdown and 100 mA maximum collector current define the switching envelope. This is a low-power device — 250 mW total dissipation in the SOT-723 package means it is suited for signal-level loads, not power switching. The 200 MHz transition frequency is high enough for basic switching up into the low-MHz range, but the pre-biased resistors will dominate the switching speed in practice. Vce saturation is 300 mV at 1 mA base and 20 mA collector — that is the on-state voltage drop when fully driven. The DC current gain minimum of 20 at 20 mA collector current, 5 V Vce, tells you the forced beta in saturation is low, which is typical for a pre-biased part where the resistor ratio sets the drive.